2 files changed, 108 insertions, 22 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9d9002ed77b..0a2af0472a9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2012-12-11  Eli Zaretskii  <eliz@gnu.org>
+
+        * xdisp.c (handle_face_prop): Fix logic of computing
+        it->start_of_box_run_p.
+        (append_space_for_newline): If the glyph row is R2L, reset the
+        iterator's end_of_box_run_p flag before prepending the space glyph.
+        (extend_face_to_end_of_line): If the glyph row is R2L, reset the
+        iterator's start_of_box_run_p flag before prepending the stretch.
+        (append_glyph, produce_image_glyph, append_composite_glyph)
+        (append_stretch_glyph, append_glyphless_glyph): Reverse the
+        left_box_line_p and right_box_line_p flags of the glyph for R2L
+        glyph rows.  (Bug#13011)
+
 2012-12-11  Dmitry Antipov  <dmantipov@yandex.ru>
 
         * buffer.c (Fset_buffer_multibyte): Do not force redisplay
diff --git a/src/xdisp.c b/src/xdisp.c
index ccd0bb07487..c6f4b440e74 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -3760,18 +3760,26 @@ handle_face_prop (struct it *it)
       if (new_face_id != it->face_id)
         {
           struct face *new_face = FACE_FROM_ID (it->f, new_face_id);
+          /* If it->face_id is -1, old_face below will be NULL, see
+             the definition of FACE_FROM_ID.  This will happen if this
+             is the initial call that gets the face.  */
+          struct face *old_face = FACE_FROM_ID (it->f, it->face_id);
 
-          /* If new face has a box but old face has not, this is
-             the start of a run of characters with box, i.e. it has
-             a shadow on the left side.  The value of face_id of the
-             iterator will be -1 if this is the initial call that gets
-             the face.  In this case, we have to look in front of IT's
-             position and see whether there is a face != new_face_id.  */
-          it->start_of_box_run_p
-            = (new_face->box != FACE_NO_BOX
-               && (it->face_id >= 0
-                   || IT_CHARPOS (*it) == BEG
-                   || new_face_id != face_before_it_pos (it)));
+          /* If the value of face_id of the iterator is -1, we have to
+             look in front of IT's position and see whether there is a
+             face there that's different from new_face_id.  */
+          if (!old_face && IT_CHARPOS (*it) > BEG)
+            {
+              int prev_face_id = face_before_it_pos (it);
+
+              old_face = FACE_FROM_ID (it->f, prev_face_id);
+            }
+
+          /* If the new face has a box, but the old face does not,
+             this is the start of a run of characters with box face,
+             i.e. this character has a shadow on the left side.  */
+          it->start_of_box_run_p = (new_face->box != FACE_NO_BOX
+                                    && (old_face == NULL || !old_face->box));
           it->face_box_p = new_face->box != FACE_NO_BOX;
         }
     }
@@ -18718,6 +18726,7 @@ append_space_for_newline (struct it *it, int default_face_p)
           int saved_char_to_display = it->char_to_display;
           int saved_x = it->current_x;
           int saved_face_id = it->face_id;
+          int saved_box_end = it->end_of_box_run_p;
           struct text_pos saved_pos;
           Lisp_Object saved_object;
           struct face *face;
@@ -18739,6 +18748,16 @@ append_space_for_newline (struct it *it, int default_face_p)
             it->face_id = it->saved_face_id;
           face = FACE_FROM_ID (it->f, it->face_id);
           it->face_id = FACE_FOR_CHAR (it->f, face, 0, -1, Qnil);
+          /* In R2L rows, we will prepend a stretch glyph that will
+             have the end_of_box_run_p flag set for it, so there's no
+             need for the appended newline glyph to have that flag
+             set.  */
+          if (it->glyph_row->reversed_p
+              /* But if the appended newline glyph goes all the way to
+                 the end of the row, there will be no stretch glyph,
+                 so leave the box flag set.  */
+              && saved_x + FRAME_COLUMN_WIDTH (it->f) < it->last_visible_x)
+            it->end_of_box_run_p = 0;
 
           PRODUCE_GLYPHS (it);
 
@@ -18752,6 +18771,7 @@ append_space_for_newline (struct it *it, int default_face_p)
           it->len = saved_len;
           it->c = saved_c;
           it->char_to_display = saved_char_to_display;
+          it->end_of_box_run_p = saved_box_end;
           return 1;
         }
     }
@@ -18841,7 +18861,7 @@ extend_face_to_end_of_line (struct it *it)
           struct glyph *g;
           int row_width, stretch_ascent, stretch_width;
           struct text_pos saved_pos;
-          int saved_face_id, saved_avoid_cursor;
+          int saved_face_id, saved_avoid_cursor, saved_box_start;
 
           for (row_width = 0, g = row_start; g < row_end; g++)
             row_width += g->pixel_width;
@@ -18856,6 +18876,7 @@ extend_face_to_end_of_line (struct it *it)
               saved_avoid_cursor = it->avoid_cursor_p;
               it->avoid_cursor_p = 1;
               saved_face_id = it->face_id;
+              saved_box_start = it->start_of_box_run_p;
               /* The last row's stretch glyph should get the default
                  face, to avoid painting the rest of the window with
                  the region face, if the region ends at ZV.  */
@@ -18863,11 +18884,13 @@ extend_face_to_end_of_line (struct it *it)
                 it->face_id = default_face->id;
               else
                 it->face_id = face->id;
+              it->start_of_box_run_p = 0;
               append_stretch_glyph (it, make_number (0), stretch_width,
                                     it->ascent + it->descent, stretch_ascent);
               it->position = saved_pos;
               it->avoid_cursor_p = saved_avoid_cursor;
               it->face_id = saved_face_id;
+              it->start_of_box_run_p = saved_box_start;
             }
         }
 #endif  /* HAVE_WINDOW_SYSTEM */
@@ -23901,8 +23924,18 @@ append_glyph (struct it *it)
       glyph->type = CHAR_GLYPH;
       glyph->avoid_cursor_p = it->avoid_cursor_p;
       glyph->multibyte_p = it->multibyte_p;
-      glyph->left_box_line_p = it->start_of_box_run_p;
-      glyph->right_box_line_p = it->end_of_box_run_p;
+      if (it->glyph_row->reversed_p && area == TEXT_AREA)
+        {
+          /* In R2L rows, the left and the right box edges need to be
+             drawn in reverse direction.  */
+          glyph->right_box_line_p = it->start_of_box_run_p;
+          glyph->left_box_line_p = it->end_of_box_run_p;
+        }
+      else
+        {
+          glyph->left_box_line_p = it->start_of_box_run_p;
+          glyph->right_box_line_p = it->end_of_box_run_p;
+        }
       glyph->overlaps_vertically_p = (it->phys_ascent > it->ascent
                                       || it->phys_descent > it->descent);
       glyph->glyph_not_available_p = it->glyph_not_available_p;
@@ -23976,8 +24009,18 @@ append_composite_glyph (struct it *it)
         }
       glyph->avoid_cursor_p = it->avoid_cursor_p;
       glyph->multibyte_p = it->multibyte_p;
-      glyph->left_box_line_p = it->start_of_box_run_p;
-      glyph->right_box_line_p = it->end_of_box_run_p;
+      if (it->glyph_row->reversed_p && area == TEXT_AREA)
+        {
+          /* In R2L rows, the left and the right box edges need to be
+             drawn in reverse direction.  */
+          glyph->right_box_line_p = it->start_of_box_run_p;
+          glyph->left_box_line_p = it->end_of_box_run_p;
+        }
+      else
+        {
+          glyph->left_box_line_p = it->start_of_box_run_p;
+          glyph->right_box_line_p = it->end_of_box_run_p;
+        }
       glyph->overlaps_vertically_p = (it->phys_ascent > it->ascent
                                       || it->phys_descent > it->descent);
       glyph->padding_p = 0;
@@ -24154,8 +24197,18 @@ produce_image_glyph (struct it *it)
           glyph->type = IMAGE_GLYPH;
           glyph->avoid_cursor_p = it->avoid_cursor_p;
           glyph->multibyte_p = it->multibyte_p;
-          glyph->left_box_line_p = it->start_of_box_run_p;
-          glyph->right_box_line_p = it->end_of_box_run_p;
+          if (it->glyph_row->reversed_p && area == TEXT_AREA)
+            {
+              /* In R2L rows, the left and the right box edges need to be
+                 drawn in reverse direction.  */
+              glyph->right_box_line_p = it->start_of_box_run_p;
+              glyph->left_box_line_p = it->end_of_box_run_p;
+            }
+          else
+            {
+              glyph->left_box_line_p = it->start_of_box_run_p;
+              glyph->right_box_line_p = it->end_of_box_run_p;
+            }
           glyph->overlaps_vertically_p = 0;
           glyph->padding_p = 0;
           glyph->glyph_not_available_p = 0;
@@ -24297,8 +24350,18 @@ append_stretch_glyph (struct it *it, Lisp_Object object,
       glyph->type = STRETCH_GLYPH;
       glyph->avoid_cursor_p = it->avoid_cursor_p;
       glyph->multibyte_p = it->multibyte_p;
-      glyph->left_box_line_p = it->start_of_box_run_p;
-      glyph->right_box_line_p = it->end_of_box_run_p;
+      if (it->glyph_row->reversed_p && area == TEXT_AREA)
+        {
+          /* In R2L rows, the left and the right box edges need to be
+             drawn in reverse direction.  */
+          glyph->right_box_line_p = it->start_of_box_run_p;
+          glyph->left_box_line_p = it->end_of_box_run_p;
+        }
+      else
+        {
+          glyph->left_box_line_p = it->start_of_box_run_p;
+          glyph->right_box_line_p = it->end_of_box_run_p;
+        }
       glyph->overlaps_vertically_p = 0;
       glyph->padding_p = 0;
       glyph->glyph_not_available_p = 0;
@@ -24750,8 +24813,18 @@ append_glyphless_glyph (struct it *it, int face_id, int for_no_font, int len,
       glyph->slice.glyphless.lower_yoff = lower_yoff;
       glyph->avoid_cursor_p = it->avoid_cursor_p;
       glyph->multibyte_p = it->multibyte_p;
-      glyph->left_box_line_p = it->start_of_box_run_p;
-      glyph->right_box_line_p = it->end_of_box_run_p;
+      if (it->glyph_row->reversed_p && area == TEXT_AREA)
+        {
+          /* In R2L rows, the left and the right box edges need to be
+             drawn in reverse direction.  */
+          glyph->right_box_line_p = it->start_of_box_run_p;
+          glyph->left_box_line_p = it->end_of_box_run_p;
+        }
+      else
+        {
+          glyph->left_box_line_p = it->start_of_box_run_p;
+          glyph->right_box_line_p = it->end_of_box_run_p;
+        }
       glyph->overlaps_vertically_p = (it->phys_ascent > it->ascent
                                       || it->phys_descent > it->descent);
       glyph->padding_p = 0;